EP1354150B1 - Hydrodynamic clutch device - Google Patents

Abstract

A hydrodynamic clutch device, in particular a torque converter or fluid clutch, includes a housing, a turbine wheel in the housing, and a torque-converter lock-up clutch, which is used to selectively produce a torque-transfer connection between the turbine wheel and the housing. The torque-converter lock-up clutch includes at least one substantially annular friction element, which is connected to the turbine wheel in order to rotate with the latter about a rational axis, the element having a friction surface region and a contact element. The contact element is connected to the housing in order to rotate with the latter about the rotational axis and impinges upon the friction surface region of the friction elements to produce the torque-transfer connection between the turbine wheel and the housing. The contact element is connected to the housing assembly in a rotationally rigid manner in a zone lying radially outside the friction surface region.

Description

The invention relates to a hydrodynamic coupling device, in particular Torque converter or fluid coupling.

By Japanese Patent Publication P 2000-230625 A, which is to be regarded as the closest prior art, is a hydrodynamic coupling device, designed as a torque converter, known. The coupling device comprises a housing arrangement and an in the housing assembly provided impeller, a turbine wheel and a Guide wheel for forming a hydrodynamic circuit. Furthermore, one is Bypass clutch arrangement provided by which optionally a Torque transmission connection between the turbine wheel and the Housing arrangement can be produced. The lock-up clutch assembly has a via a torsional vibration damper with the turbine to common rotation about an axis of rotation, essentially ring-like friction element with a Reiboberflächenbereich on, as well as a Pressing element, which with the housing assembly for common rotation is connected about the axis of rotation and through which the Reiboberflächenbereich the at least one friction element for producing the Torque transmission connection between turbine wheel and housing assembly can be acted upon. The pressing element is radially outside the Reiboberflächenbereiches substantially torsionally rigid with the housing assembly connected.

In such a hydrodynamic coupling device can in particular in a state in which at least a part of the over one Drive train to be transmitted torque via the lock-up clutch assembly passed from the housing assembly to the turbine wheel is intercepted, occurring in the drive system torsional vibrations be that in the lock-up clutch assembly a certain slip is allowed, so that torque peaks to a relative rotation can lead between the housing assembly and the turbine wheel. This leads to a comparatively large burden in the area of Bypass clutch assembly rubbing against each other components or surface areas, since at least for larger torque fluctuations occurring, absorbed by slippage loss in heat is converted.

In order to meet the requirement for ever greater potential losses in the The range of the lock-up clutch assembly, Systems have been developed, as described for example in WO 00/03158 are described. In the known from this document hydrodynamic Torque converter has two lockup clutch assembly friction elements coupled to the turbine wheel for common rotation, between which one with the housing assembly for common rotation coupled Zwischenreibelement is positioned. By the radially inside the Reiboberflächenbereiches attached to the housing assembly and as Anpresselement acting clutch pistons are the individual Friction surface areas of the friction elements, the Zwischenreibelements, the Clutch piston and the housing assembly in mutual interaction brought. By providing several staggered, together in Interaction engageable Reibflächenpaarungen can without significant Space requirements, the total provided friction surface significantly be enlarged. This has the consequence that also in the slip operation occurring power dissipation over a larger surface and thus distributed improved and can be dissipated faster.

In the coupling device according to WO 00/03158 is for Connection of the friction elements with the turbine wheel, a connection assembly provided, which "bypasses" the pressing element on its outer circumference. These Connection consumes space and increases the weight of the Coupling device. The arrangement of additional mass in the radially outer Area also leads to an increase in the Moment of inertia of the turbine wheel.

In the aforementioned coupling device is in view of the Total weight to note that further the storage of the radially inner region of the pressing member at a for this axially from the housing assembly in the interior protruding section takes place.

The invention is based on the object, a hydrodynamic Form coupling device such that they are simple constructive Building high power losses in the area of Bypass clutch arrangement endures.

The invention is defined by the features of claim 1. According to the invention, friction elements, if desired via a Torsional vibration damper, radial within the friction surface area in Essentially rigidly connected to the turbine wheel. For example, can each friction member comprises a friction member support portion extending from the Friction surface area extending radially inward extends. As several Friction elements are provided, each of these elements can be such having running Reibelementträgerabschnitt. However, it is also conceivable a radially inwardly extending, the friction elements common Reibelementträgerabschnitt is provided, which at its inner circumference with the Turbine, in particular the turbine hub, and is connected to his Outer circumference a Reibelementmitnehmer for entrainment, in particular positive entrainment that carries individual friction elements. A common Reibelementträger can for example by means of a weld with the Turbine be connected. It should be noted that at one Welding in the turbine hub advantageously any deformation is avoided in the turbine wheel shell.

In the case of the plurality of friction elements, in each case between Reiboberflächenbereichen two adjacent friction elements in the Essentially torsionally rigid connected to the pressing element Intermediate friction element arranged. The torsionally rigid connection with the Pressing ensured in a simple way the entrainment of the Zwischenreibelementes upon rotation of the housing assembly. Prefers each intermediate friction element or a plurality extends Zwischenreibelementen common Zwischenreibelementträger in Engaging cut-outs of the pressing element intervening.

Preferably, the contact pressure element is via an elastic device, in particular a tangential leaf spring arrangement, with the housing arrangement connected. To a comparatively by such elastic means high torque transfer between the contact pressure and the To enable housing arrangement, this device should be in a radial be arranged outside region of the pressing element. In case of a Tangentialblattfederanordnung it is expedient, the contact pressure on the Provide outer circumference with radial indentations, so that during assembly the coupling device, the leaf springs first on the outer circumference attached to remaining radial tabs of the pressing member, e.g. riveted, can be to later in the range of radial indentations located free ends of the leaf springs with an axially extending inner surface of the Housing arrangement to connect. A housing side riveting the Leaf spring ends are preferably made on housing pin, which by a local Deformation (e.g., impressions) of the housing material are formed.

The one or more Reibelementträgerabschnitte should save material in the Extend substantially axially. However, it is quite possible one of them deviating course, in particular a substantially rectilinear oblique Course to provide, for example, an axial offset between the Frictional surface area and the point at which the Connection to the turbine takes place.

A particularly easy to implement construction of a hydrodynamic Coupling device, which according to the principle of a 2-pipe system works, can be obtained by the fact that by the pressing element Interior of the housing assembly in a first space area, in which the turbine wheel is arranged, and a second space area is divided and that for the exchange of provided in the interior of working fluid in the first space area working fluid introduced and from the second Sphere range working fluid is divertable or vice versa. To be at one such system despite a radially outer seal of the pressing through the abutting friction surface areas in the engaged Condition of the lock-up clutch assembly a fluid exchange to enable proposed that in the pressing element radially within the Reiboberflächenbereiches at least one fluid passage opening to Allow fluid exchange between the first space area and the second space area is provided. Furthermore, to improve a Fluid cooling in the engaged or slipping state further proposed, in the friction surface region of the at least one friction element preferably formed with bow-like shape Flow channel arrangement is provided. This flow channel arrangement is then preferably open to the two space areas, so conditionally by the pressure difference already present in these clutch states between the two spatial areas a fluid passage through the Flow channel arrangement will take place while the in this Spatial area resulting heat energy can be dissipated efficiently.

Of course, the coupling device according to the invention also as be formed so-called 3-pipe system, wherein the two fluid lines for fluid exchange and another fluid line for fluid pressure controlled Operation of the clutch piston is provided.

Preferably, it is provided in the coupling device according to the invention, that the housing assembly to the contour of the lock-up clutch assembly adapted shape with an axial bulge in the Has area of the lock-up clutch assembly. This measure has As a result, the housing arrangement in particular in their also for the Bridging grouping arrangement or for their effect provided area is designed with higher rigidity. This leads to a significantly lower bulge or a much lower Inflating the housing assembly under the inside of the housing prevailing fluid pressure. Therefore, it may be relatively even in the radial direction wide Reibflächenbereichen not induced by a bulge Edge load of friction linings or the like come.

For coupling the coupling device according to the invention to a Drive shaft may be a substantially ring-like coupling element be provided in its radially inner region to an outside of the Housing assembly, preferably by laser welding, is connected and in its radially outer region for coupling to one with a drive shaft firmly connected or connectable second coupling element is formed.

To obtain a favorable mass distribution with the consequence of a lower Mass moment of inertia or to increase the Friction surface areas can provide that a ratio of a Flow outside diameter in the region of the turbine wheel to a Friction outside diameter of the at least one friction element in the range of 1.30 to 1.80, preferably 1.35 to 1.70, and / or that a ratio a Reibausßendurchmessers of the at least one friction element to a Reibinnendurchmesser the at least one friction element in the range of 1.10 to 1.30, preferably 1.15 to 1.25.

Fig. 1

eine Teil-Axialschnittansicht einer erfindungsgemäßen hydrodynamischen Kopplungseinrichtung, und

Fig. 2

eine Detailansicht in Richtung des Pfeils II in Fig. 1.

The invention will be described in more detail below with reference to an embodiment with reference to the accompanying drawings. It shows:

Fig. 1

a partial axial sectional view of a hydrodynamic coupling device according to the invention, and

Fig. 2

a detailed view in the direction of arrow II in Fig. 1st

FIG. 1 shows a hydrodynamic torque converter 10 comprising a Housing assembly 12, one provided in the housing assembly 12 Turbine 14 and a lock-up clutch assembly 16.

The housing assembly 12 includes a housing cover 18 which is in its radially outer region, for example by welding with a Impeller shell 20 is firmly connected. Radial inside is the impeller shell 20 fixedly connected to a pump hub 22. At her for Housing interior 24 facing the inside carries the impeller shell 20th a plurality of circumferentially successive impeller blades 26. The pump shell 20 forms together with the impeller hub 22 and the Pumpenradschaufein 26 substantially an impeller 28. The housing cover 18 is on its outside with a coaxial with a Rotary axis A arranged centering pin 34 is provided, which in a corresponding centering recess of a drive shaft, not shown, For example, crankshaft of an internal combustion engine, to align the Rotary axis A of the torque converter 10 with respect to the axis of rotation of the Drive shaft is used.

The turbine wheel 14 is disposed in the interior 24 of the transducer 10 and comprises in the radially outer region a turbine wheel 36, which at its the impeller 28 side facing a plurality of turbine blades 38 carries. Radially inside is the turbine wheel 36, for example by Welding or screwing at 39 with a turbine hub 40 fixed connected. The turbine hub 14 in turn can be equipped with an output shaft, For example, a transmission input shaft, rotatably connected.

Axially between the impeller 28 and the turbine 14 is a stator 42nd intended. The stator 42 comprises on a Leitradring 44 a plurality of Leitradschaufeln 46, which between the radially inner end portions of the Impeller blades 26 and the turbine blades 38 are positioned. Of the Leitradring 44 is via a freewheel assembly 48 on a not shown Support member, such as a hollow support shaft, in a direction around the Rotatable about A rotation, against rotation in the other direction however, worn blocked. In the axial direction, the stator 42 is over two Bearing assemblies 50, 52 with respect to the impeller 28 on the one hand and on the other hand axially supported with respect to the turbine wheel 14.

The lock-up clutch assembly 16 is used to produce a direct mechanical torque transmission connection between the turbine wheel 14 and the housing assembly 12 and includes a coupling piston 56, the with a radially inner cylindrical portion on an outer circumferential surface the turbine hub 40 via a sliding bearing 58 axially displaceable and relative to Turbine 14 is rotatably mounted. The clutch piston 56 is at its radial outer end region via an elastic arrangement, in the example shown a Tangentialblattfederanordnung 60, substantially torsionally rigid with the Housing cover 18 connected. The clutch piston 56 is thereby relative the housing cover 18 held axially movable.

The lockup clutch assembly 16 further includes two louvers or Friction elements 62, 64 which in their radially outer region in each case at both axial faces friction linings 66, 68, 70, 72 wear. In her radially inner Section, each friction element 62, 64 comprises a friction element carrier section 74, 76, which differs from one by the extent of the friction linings 66, 68, 70, 72nd defined friction surface area R starting radially inward extends. in the illustrated embodiment, the Reibelementträgerabschnitte 74, 76th integral with the friction linings bearing portions of the friction elements 62, 64 trained. The Reibelementträgerabschnitte 74, 76 are at their radial inner end portion formed with an internal toothing, which with a corresponding outer toothing 80 of the turbine hub 40 in Mitnahmeeingriff stands. It is thus a torsionally rigid connection between the Friction elements 62, 64 and the turbine 14 created.

Axial between the two friction elements 62, 64 is an intermediate friction element 82, extending from the Reiboberflächenbereich R radially outward in Mitnahme recesses 84 of the clutch piston 56 engaging extends. It is thus a torsionally rigid connection between the intermediate friction element 82 and the clutch piston 56 and thus the housing assembly 12 created.

The interior 24 of the housing assembly 12 is through the clutch piston 56 in a first space area 86, in which the turbine wheel 14 is arranged is divided, and a second space area 88. For the production of Bridging state, we the fluid pressure in the space area 86 on the im Room area 88 prevailing fluid pressure also increased. To increase the Fluid pressure in the space region 86 can via a passage opening arrangement 90th in the region of the stator 42 of a fluid pump, not shown on a for example, between the output shaft, not shown, and a Support hollow shaft formed intermediate space fluid introduced into the space area 86 become. In the unbridged state, the fluid can then move away from the space 86 enter under the flow around the friction elements 62, 64 in the space area 88 and via a fluid leading radially inward passage opening arrangement 92 through the output shaft and from there to a not shown Flow fluid reservoir. In the bridged state, in which the pressure of the Clutch piston 56 to a fluid seal in the region of the friction linings 66, 68, 70, 72, also to allow a fluid exchange is in the Clutch piston 56 radially within the Reiboberflächenbereiches R. at least one fluid passage opening 94 is provided, which is the fluid exchange between the first space area 86 and the second space area 88 allows. Furthermore, the friction linings 66, 68, 70, 72 can Belungsnutungen with For example, arc-like course have, in the radially outer region are open to the space area 86 and in the radially inner region to Room area 88 are open towards, so even in the fully bridged or in the slipping state in the region of the friction linings 66, 68, 70, 72nd resulting frictional heat dissipated by the fluid flow faster can be.

To achieve a further minimization of the mass moment of inertia, the Reibaußendurchmesser b of the friction linings 66, 68, 70, 72 comparatively small held. Thus, in the preferred case, a ratio of Fluid flow outside diameter a, which approximately the Outer diameter of the turbine wheel 32 corresponds, with respect to Friction outside diameter b has a value in the range of 1.35 to 1.70.

Furthermore, the ratio between the Reibaußendurchmesser b and the friction inner diameter c of the friction linings 66, 68, 70, 72 preferably in a range of 1.15 to 1.25. This leads to a comparatively large Radial extension of the annular friction linings and thus to a comparatively large possible power loss in the area of Lockup clutch arrangement.

The housing assembly 12 has one to the contour of the lock-up clutch assembly 16 adapted shaping with an axial bulge 96 in the region of the lock-up clutch assembly 16 on. By the radial both sides of this bulge 96 bent contour of the housing cover 18th Thus, an advantageous stiffening of the housing assembly 12 is created. This has the consequence that provided by the in the interior 24 under pressure Working fluid bulging or swelling of the housing 12 with the adverse consequence of an edge load in the region of the outer friction lining 66 can be avoided. Instead of the axial bulge 96 may alternatively also be provided an axial recess, through which the same advantageous Effect can be achieved and beyond the axial space on can be downsized. In the latter case, it is for optimal use of the Space favorable when the friction surface area R of Bypass clutch assembly 16 completely radially within the radial Center of the turbine shell 36 is arranged.

It should be noted that the torque converter 10 of course also more than two friction elements 62, 64, for example, three friction elements, and then a correspondingly larger number of Zwischenreibelementen 82nd can have. Also, only one friction element can be used.

Another advantage of the illustrated torque converter 10 is the type and Way of connecting it to a drive shaft. It can be seen in FIG. 1 left a ring-shaped coupling element 98 which, for example, in is formed bent axial direction and shaped, for example, of sheet metal is. In its radially inner region, this coupling element 98 is preferably attached by laser welding to the outside of the housing cover 18.

The laser welding is advantageous here, since it virtually no deformation of the Casing 18 results in and any deformation in the area, in which the housing cover 18 provides a friction surface on its inside, would be disadvantageous. In its radially outer region, the coupling element 98 carries a plurality of nut elements 100 or the like, in which bolts or The like can be screwed to the coupling element 98 with a flex plate or the like to connect, with such a plate in is known in its radially inner region to a drive shaft, e.g. a crankshaft flange, can be screwed.

FIG. 2 shows a view marked II in FIG. 1 in the region of FIG Essentially torsionally rigid connection between the clutch piston 56 and the inside of the housing cover 18. It can be seen on the outer circumference of the Clutch piston 56 one of a plurality of radial recesses 102, in whose Area in each case a housing-side end of a tangential leaf spring 104 by Riveting on a cap pin 106 is connected. The piston end the tangential leaf spring 104 is by riveting at 108 at radial Lugs 110 of the clutch piston 56 attached. In this way are about the The circumference of the clutch piston 56 distributes several tangential blade springs 104 provided in the operation of the lock-up clutch assembly 16 ensure required Axialverschiebbarkeit the clutch piston 56.

Also distributed distributed in the circumferential direction are the Mitnahmeaussparungen 84 of the clutch piston 56, in which radially outward projecting tabs of Zwischenreibelementes 82 intervene. These Mitnahme Reussungen 84 can alternatively also each by a section (e.g., the bottom) of the radial indentations 102, e.g. as it is shown by dashed lines in Figure 2.

In a preferred embodiment, the cap pins 106 are as in FIG. 1 represented formed by pressing the housing cover 18.

Of course, in the coupling device according to the invention in different areas are being changed without the changes Diverge principles of the invention. For example, that or the Zwischenreibelemente be rotatably coupled to the housing cover. Also could be radially within the Reiboberflächenbereiches a Friction elements common Reibelementträger be provided, the individual friction elements axially displaceable holds and at its radially inner Area is rotatably coupled to the turbine wheel. Such a friction element carrier can also be designed as a torsional vibration damper to to meet special vibration requirements.

Claims (9)

1. Hydrodynamic coupling device, in particular torque converter or fluid clutch, characterized by:

   a housing arrangement (12),

   a turbine wheel (14) provided in the housing arrangement (12),

   a lock-up clutch arrangement (16) enabling the optional production of a torque transmission connection between the turbine wheel (14) and the housing arrangement (12),

   the lock-up clutch arrangement (16) comprising:

   a plurality of substantially annular friction elements (62, 64) which are connected to the turbine wheel (14) for rotation together about an axis of rotation (A) and have friction surface regions (R), the friction elements (62, 64) being connected substantially rigidly in terms of rotation to the turbine wheel (14) radially within the friction surface region (R),

   a pressure element (56) which is connected to the housing arrangement (12) for rotation together about the axis of rotation (A) and can be used to act upon the friction surface regions (R) of the friction elements (62, 64) to produce the torque transmission connection between the turbine wheel (14) and the housing arrangement (12), and which is connected substantially rigidly in terms of rotation to the housing arrangement (12) radially outside the friction surface regions (R), and

   an intermediate friction element (82) being arranged in each case between friction surface regions (R) of two adjacent friction elements (62, 64) and being connected substantially rigidly in terms of rotation to the pressure element (56).
2. Hydrodynamic coupling device according to Claim 1, characterized in that the pressure element (56) is connected to the housing arrangement (12) via an elastic device (60), in particular a tangential leaf-spring arrangement.
3. Hydrodynamic coupling device according to Claim 1 or 2, characterized in that the pressure element (56) is mounted (58) so as to be axially displaceable on the turbine wheel (14) and rotatable relative to the turbine wheel (14).
4. Hydrodynamic coupling device according to Claim 1, characterized in that the intermediate friction element (82) extends in a manner which engages in driving cut-outs (84) in the pressure element (56).
5. Hydrodynamic coupling device according to one of Claims 1 to 4, an inner space (24) of the housing arrangement (12) being divided by the pressure element (56) into a first space region (86) in which the turbine wheel (14) is arranged and into a second space region (88), and, in order to exchange operating fluid which is provided in the inner space (24), it being possible to introduce operating fluid into the first space region (86) and to remove operating fluid out of the second region (88) or vice versa, characterized in that at least one fluid passage opening (94) is provided in the pressure element (56) radially within the friction surface region (R) in order to make the exchange of fluid possible between the first space region (86) and the second space region (88).
6. Hydrodynamic coupling device according to Claim 5, characterized in that a flow-channel arrangement preferably having an arcuate shape is provided in the friction surface regions (R) of the friction elements (62, 64).
7. Hydrodynamic coupling device according to one of Claims 1 to 6, characterized in that the housing arrangement (12) has a shaping which is matched to the contour of the lock-up clutch arrangement (16) and has an axial hollowed-out portion (96) in the region of the lock-up clutch arrangement (16).
8. Hydrodynamic coupling device according to one of Claims 1 to 7, characterized by a first coupling element (98) which is of substantially annular design, is joined in its radially inner region to an outer side of the housing arrangement (12), preferably by laser welding, and is designed in its radially outer region for coupling to a second coupling element (100) which is connected fixedly or can be connected fixedly to a drive shaft.
9. Hydrodynamic coupling device according to one of Claims 1 to 8, characterized in that a ratio of a flow outside diameter (a) in the region of the turbine wheel (14) to a friction outside diameter (b) of the friction elements (62, 64) is in the range from 1.30 to 1.80, preferably from 1.35 to 1.70, and/or in that a ratio of a friction outside diameter (b) of the friction elements (62, 64) to a friction inside diameter (c) of the friction elements (62, 64) is in the range from 1.10 to 1.30, preferably from 1.15 to 1.25.

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